This package implements privates, the leaves of command
hierarchies. While each private can execute only a single action they
have parameters, i.e. arguments and options with which to configure
the behaviour of their action.

The command prefix to invoke when this private is selected for
execution. It takes a single argument, the instance command of the
hidden cmdr::config container holding the private's
parameters. The result of the action, if there is any, is ignored by
the framework.

The instance API is not public. It is used internally by the framework
during the parsing of a command hierarchy specification to configure
the private instances, and when processing a command line at
runtime to manage word-completion, etc.

It is described here for use by developers maintaining,
modifying and extending the framework itself. A user of the framework
has no need for it, although they have indirect access through
parameters and their container.

This method parses the words of the command line, matching them
to the parameters of the private, be they arguments, or options. When
done without error it invokes the action of the private with the
filled container of parameters.

This method specifies a command prefix to wrap around the parsing of
the command line for the private, and the execution of its action.

cmd-prefix cmd

A command prefix taking a single argument, a script. The command
prefix has to execute this script in its caller's context. The script
will parse words for the private,m and perform its action. The command
prefix then has the responsbility to perform any custom cleanup action
required by the application using the framework to prevent leakage of
data between multiple commands executed one after the other (i.e. in
an interactive shell run by the framework).

This method returns the instance command of the sub-ordinate with the
given path of names. An error is thrown if such a sub-ordinate
does not exist, i.e. whenever path is not empty, as a private
has no sub-ordinates, ever.

Note, as implied above, an empty path is allowed and
refers to the private itself.

See also method find of cdmr::officer for the
high-end of the recursion which may end in this method.

This method returns the help information for the private and its
parameters. The prefix, if specified provides the name of the
private within the help data. It defaults to the empty string.
The result of the command is a structure of the form
described in section Help Information.